hasura/graphql-engine · error · AggregateBooleanExpressionError

the order by expression '{order_by_expression}' could not be

Error message

the order by expression '{order_by_expression}' could not be found

What it means

When resolving aggregate boolean expressions that involve ordering (e.g. finding min/max by ordering), the referenced order-by expression must exist among those defined on the aggregate expression. This error is thrown when the qualified order-by expression name cannot be found.

Source

Thrown at v3/crates/metadata-resolve/src/stages/aggregate_boolean_expressions/types.rs:228

        "type mismatch between the '{count_type}' aggregate (return type: '{count_return_type}') and the specified boolean expression type '{boolean_expression_type}' (operand type: '{boolean_expression_operand_type}')"
    )]
    CountAggregateTypeMismatch {
        count_type: CountAggregateType,
        count_return_type: QualifiedTypeName,
        boolean_expression_type: BooleanExpressionTypeIdentifier,
        boolean_expression_operand_type: QualifiedTypeName,
    },

    #[error(
        "the operand type '{operand_type}' does not match the operand type of the filter boolean expression type '{boolean_expression_type}': '{boolean_expression_operand_type}'"
    )]
    FilterInputFilterExpressionTypeMismatch {
        operand_type: QualifiedTypeName,
        boolean_expression_type: Qualified<CustomTypeName>,
        boolean_expression_operand_type: QualifiedTypeName,
    },

    #[error("the order by expression '{order_by_expression}' could not be found")]
    OrderByExpressionNotFound {
        order_by_expression: Qualified<OrderByExpressionName>,
    },

    #[error("the field '{field_name}' is defined more than once in the comparable fields")]
    DuplicateComparableFieldsFound { field_name: FieldName },

    #[error(
        "the field '{field_name}' used in comparable fields is not an aggregatable field defined in the aggregate expression '{aggregate_expression}'"
    )]
    ComparableFieldNotFound {
        field_name: FieldName,
        aggregate_expression: Qualified<AggregateExpressionName>,
    },

    #[error(
        "the operand object type '{operand_type}' does not contain the field '{field_name}' used in the comparable fields"
    )]

View on GitHub (pinned to 724551b9ae)

Solutions

1. Check the order-by expression name in the failing metadata and confirm it exists on the aggregate expression
2. Restore or rename-back the order_by expression, or update references to its new name
3. Run metadata validation to surface dangling order-by references

Example fix

// before
order_by: MissingOrder  // not defined on aggregate expression

// after
order_by: DefinedOrder   // exists in order_by_expressions

let names: HashSet<_> = agg_expr.order_by_expressions.iter().map(|o| o.name.clone()).collect();
assert!(names.contains(&referenced_order_by), "order-by expression not defined");

fn order_by_exists(agg: &AggregateExpression, name: &str) -> bool {
    agg.order_by_expressions.iter().any(|o| o.name.as_str() == name)
}

match resolve(expr) {
    Err(ResolveError::OrderByExpressionNotFound { order_by_expression }) => {
        // list available order-by expressions and surface a helpful message
    }
    r => r,
}

When it happens

Trigger: Referencing an order_by expression by name in an aggregate expression where it is not defined; deleting or renaming an order-by expression in metadata while an aggregate comparison still references it.

Common situations: Renaming order_by_expressions entries in metadata without updating aggregate references; environment metadata drift where the order-by expression exists in one env but not another; typos in the order-by expression name.

Related errors

• the field '{field_name}' used in comparable fields is not an
• could not find a scalar-operanded boolean expression type na
• type mismatch between the aggregation function '{aggregation
• the aggregation function '{aggregation_function_name}' retur
• the {count_type} aggregation cannot be compared to because i

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/46ed29b775846b71. Report an issue: GitHub.